Gas burner



. Jan. 26, 1937. FORBERG 2,069,062

/a ll 36 l 45 E A7 396- A l n 3/ L? I? 2 42 2g 43 20 25 T 24 I 2/ 33 f 22 GAS BURNER Filed May 19, 1934 2 Sheets-Sheet l INVENTOR ErT'oRNEY T. FORBERG Jan. 26, 1937.

GAS BURNER Filed May 19, 1954 2 Sheets-Sheet 2 Patented Jan. 26 1937 UNITED STATES PATENT OFFICE mesne assignments, to Serve],

Inc., Dover,

Del., a, corporation of Delaware Application May 19,- 1934, Serial No, 726,493

4 Claims. (Cl. 158-106) invention relates to gas burners and more particularly to burners of the type in which gas is mixed with air prior to emission of the gas from the burner, such as, for instance, Bunsen type burners in absorption refrigeration apparatus. v

It is an object of my invention to provide a gas burner of such type in which stoppage of primary air caused by deposit of foreign particles such as dust and lint is substantially eliminated, whereby the gas burner will require a minimum amount of attention.

In accordance with my invention, primary air flows to the burner from a point immediately adjacent the burner flame and in a direction substantially opposite to the direction of air flow at the flame, whereby the air is cleansed of lint, dust, and other foreign particles by the combined effects of inertia and incineration.

The nature of my-invention and the objects and advantages thereof will be more fully apparent upon consideration of the following description and the'accompanying drawings forming a part of this specification and of which:

Fig. 1 is a sectional'view of a gas'burner em bodying my invention;

Fig. 2, an end view of the burner;

Fig. 3, atop view of the burner; and

Fig. 4, aside view of the burner mounted in position for heating the generator of an absorption type refrigerator.

Referring more particularly to Fig. 1 of the drawings, the burner body III is provided with a gas supply passage II, suitably threaded at itsupper end, I2, for connection to a gas supply'pipe. In the upper portion of passage II, there is in serted what may be generally referred to as a. safety cut-off valve assembly I3, comprising a valve body I 4, a valve member I5, a valve stem I 6. a snap action thermostatic diaphragm II, a diaphragm housing I8, and aheat conductor I9. The valve member I5 is connected'by the valve stem I6 to the center of the thermostatic diaphragm II, the periphery of which is secured in the housing I8. The heat conductor- I9 has one end located. in a position to burner'flame and the other end secured to "the housing I8, so that when the burner is lighted heat is conducted to the phragm I1. I

A second passage 20, in the lower part of the burner housing communicates at one end with the lower part of the passage II through an opening '2I. -The effective area of this opening is adjustable by turning an adjustment screw 22,

thermostatic diabe heated by. the

which'is threaded into sage I I.

the lower end of thepas- The internal threads are shown only in outline in the interest of clarity. A suitable cap screw 23 is provided for sealing the lower end of the passage II and is removable for permit- 5 ting access to the adjustment screw 22. The adjustment screw 22 may be referred to as the maximum flame adjustment screw, as its setting determines the maximum flow of gas to the burner, and therefore the maximum size of the 10 burner flame. The otherend of the passage 28 is permanently sealed by a plug 24. A third passage 25 extends through the burner housing and intersects the passage substantially at right angles. On the exterior of a boss at the 15 upper end of the passage is threaded the lower end of a cylindrical housing 26, providing a mixing chamber 2'! at the upper end of the passage 25. In the upper end of passage 25 is threaded a member 28 having a chamber the orifice well, communicating at its lower end with the passage 25, and a small orifice 30opening from the upper end of the orifice well 29 into the mixing chamber 27.

The housing 26 is provided with air ports 3i 5 for admission of primary air to the mixing chamber 21. On the housing 26 is journaled a sleeve 32 provided with openings corresponding to the air ports 3I. This sleeve is referred to as the air shutter and it will beunderstood that the turning 30 of this shutter adjusts the size of the air ports 3| and therefore the admission of primary air to the mixing chamber 21. In the lower part of the passage 25 is threaded a member 33, which may be referred to as a. turbulator. formed with a head 34, which is preferably designed to give a swirling motion to the gas entering the orifice well 29. The lower end of the passage 25 is sealed by a suitable cap screw 35,

which is removable to allow adjustment of the tugbulator 33. The housing 26 is formed with a re tricted portion or partition 36 which is provided with a passage 31 opening into the top of the mixing chamber 21 and in line with the orlflcc 30. In the upper end of the passage 31 is threaded the lower-end of the burner tube 38. The upper end of the' burner tub is provided with a cap -39.having suitable openings 40. A tube 4|"is positioned concentrically around the burner tube 38. The lower end of the tube 4| is secured by screws 42 to the upturned rim 43 of a flange on the lower .end of the air shutter 32. The upper end 'of the tube 4| terminates closely adjacent the openings 40 in the burner cap 38. Suitable lugs 44 may be provided on the burner 29, referred to as 2 This member is 35,

. the flow of air is in cap 40 to aid in maintaining the upper end of the tube 4| in position concentrically with respect be formed by striking out portions of the air f,

shutter 32 which is fabricated of resilient metal.

In operation, a flame conductor l9, which raises the temperature of the thermostatic diaphragm until the latter snaps to a position opposite that shown in Fig. 1, openingthe safety cut-off valve l5. Gasenters the inlet l2 and flows through passage opening 2|, passage 20, passage 25, orifice well 29, and the orifice into the mixing chamber 21. gas passes through the burner oriflce, primary air is entrained through the air ports 3|. The resulting mixture of air and gas flows through passage 31, burner tube 38, and the openings 40 in the burner cap 39 where the secondary air is encountered and combustion takes place.

The flame impinges upon the conductor l9 so that the temperature of the thermostatic diaphragm I1 is maintained sufiiciently high for the valve |5 to remain open. If, for any reason, the burner flame becomes extinguished, the conductor l9 and thermostatic diaphragm Ill cool down until the diaphragm flexes back to the position illustrated in Fig. 1, snapping the valve |5 to its closed position, thus cutting off flow of gas to the burner.-

' During operationof the burner, the primary air which enters the mixing chamber 21, as pre-v viously described, has been drawn downwardly through the tube 4| from the region of the secondary air immediately adjacent the burner flame above the cap openings 40., Around the upper end of the tube 4| and the burner cap 39, the direction of the burner flame. This is due to heating of the air and movement of the gas and air mixture issuing through the cap openings 40 and of the products of combustion. This movement of air is indicated generally by the arrows outside of the tube 4|, in Figs. 1 and 4. Air which is tube.

4| with respect to the burner drawn downw'ardly in the tube 4|, as previously described, therefore undergoes a substantial reversal in direction adjacent the upper end of the Due to their inertia, particles of dust, lint, and'the like tend to continue in the direction established by the burner flame, thereby deserting the air which is drawn downwardly in the tube 4|. The ,close'proximity of the upper end of the tube 4| to the burner flame causes incineration of dust particles or lint including those separated from the 'air which may not have been during its flow reversal, thereby insuring delivery of clean primary air to the mixing chamber 21. The tube 4| may therefore be referred to as a dust prevention tube. extend upwardly as far as possible without blocking off the supply of secondary air to the burner.

The location of the open end of the dust tube flame is of critical importance in carrying out the present invention. If the end of the dust tube 4| is too far below the burner flame, dust will remain in the primary air entering the dust tube. If the open is applied to the heat-- the movement flue, the reversal site direction.

Tube 4| should v end of the dust tube 4| is in the combustion area of the burner flame, products of combustion will be drawn into the primary air inlet, and the dust tube will become heated by the flame. It is therefore necessary to locate the open end of the dust tube 4| as close to the burner flame as possible without causing suction of products of combustion. As indicated by the arrows in Figs. 1 and 4, air .flow within a certain distance of the .burner flame is in a direction opposite to flow of air sucked into the dust tube 4|, wherefore, if the open end of the dust tube is extended within this distance of the flame, air drawn into the dust tube 4| must undergo an abrupt reversal in direction of flow. On account of inertia, par-' ticles of dust, lint, and other foreign matter continue on far enough to be removed from the effect of the suction into the dust tube and are incinerated by the flame or carried on into the flue 49 into which the flame is projected as described below. It will now be understood that if the dust tube 4| does not project within said proper distance of the burner flame, air will be sucked into the dust tube from a zone in which there is no definite trend of air flow or in which the air flow is only at an angle to the dust tube,

in which case the suction would overcome the ter which would be drawn in with the primary air supply. Due to the high temperature immediately adjacent the burner flame, there is some dust removal effected by carrying out the invention, the important factor is the. direct oppositionof the primary air suction and flow of air in a zone adjacent the burner flame, whereby the inertia of foreign particles carries them into the secondary rather than the primary air stream.

In Fig. 4, the previously described burner is shown mounted in relationship to the heating flue of a generator in an absorption type refrigerator. Since the refrigeration apparatus forms no part of the present invention, there is shown only one end of the generator 48, provided with a heating flue 49. The burner is slidably and rotatably mounted on a rod 50. The burner is adjusted so that the flame is suitably projected into the end of the heating flue 49, and then secured by tightening the screw 5|. It will be understood that this relative position of the burner and generator is substantially the same whether the generator be of the horizontal or vertical type. With the burner thus arranged so that the flame projects into the end of a in the direction of air flow, previously described, is accentuated for the reason that a distinct current of secondary air is carried into the flue by the action of the burner flame, and the primary air is withdrawn through the burner dust tube 4|, in a substantially oppo- What I claim is:

incineration, but in 1. In a gas burner, a cylindrical housing forming a mixing chamber having a gas inlet orifice and air inlet ports, a burner tube extending from one end of said mixing chamber in line with said gas inlet orifice, an air shutter comprising a perforated sleeve journaled on said housing and having a flange at one end, a dust prevention tube located concentrically around said burner tube and shutter in spaced relation thereto, one end of said dust tube beingsecured to said flange and the other end of said dust tube terminating immediately adjacent the end 0t said burner tube, said dust tube, air shutter, and burner passage for primary air from a. point immediately adjacent the' burner flame to said air inlet ports, and a perforated cap on the end of said burner tube having radial projections extending into sliding engagement with the inner surface of said dust tube to space the open end of the dust tube withrespect to said burner tube.

2. In a gas burner, a mixing chamber having a gas inlet orifice and air inlet ports, a burner tube extending from the mixing chamberin line with'the gas inlet orifice. and means forming a passage for air to said air inlet ports and ineluding a conduit having an open end so located adjacent the'end of said burner tube that the open end of said conduit is in a zone next the burner flame in which flow of air induced by the flame is in a direction opposite to the direction of flow of air into said conduit, whereby particles of dust and the like in air flowing in said opposite direction continue to move in that direction due to their inertia and are thus removed from air drawn into said conduit.

3. In a gas burner, a mixing chamber having a gas inlet orifice and air inlet ports, a burner tube extending from the mixing chamber in line with the gas inlet orifice, and means forming a passage for air to said air inlet ports and including a tube located concentrically around said burner tube in spaced relation thereto and having an open end so located adjacentthe end of said burner tube that the open end of said air conducting tube is in a zone next the burner flame in which flow of air induced by the flame is in a direction opposite to the direction of flow of air into said'air conducting tube, whereby particles of dust and the like in air flowing in said opposite direction continue to move in that direction due to their inertia and are thus removed from air drawn into said air conducting tube.

4. In a gas burner, a mixing chamber having a gas inlet orifice and air inlet ports, a shutter for adjusting said air inlet ports, a burner tube extending from the mixing chamber in line with the gas inlet orifice, and means forming a passage for air to said air inlet ports and including a dust prevention tube located concentrically around said burner tube in spaced relation thereto; said dust prevention tube being connected to said air shutter for adjustment thereof and having an open endso, located adjacent the end of said burner tube that the open end of said dust prevention tube is in a zone next the burner flame in which flow of air induced by the flame is in a direction opposite to the direction of flow of air into said dust prevention tube, whereby particles of dust and the like in air flowing in said opposite direction continue to move in that direction due to their inertia and are thus removed from air drawn into said dust prevention tube.

TRYGVE FORCBERG. 

